[PATCH v3 2/7] clocksource: sh_cmt: Add OF support

Bastian Hecht hechtb at gmail.com
Tue Apr 9 11:06:36 EDT 2013


Hi Simon,

2013/4/9 Simon Horman <horms at verge.net.au>:
> On 木,  3月 21, 2013 at 10:07:15午後 +0900, Simon Horman wrote:
>> On Sun, Mar 17, 2013 at 04:43:46PM +0100, Bastian Hecht wrote:
>> > We add the capabilty to probe SH CMT timer devices using Device Tree
>> > setup.
>> >
>> > Signed-off-by: Bastian Hecht <hechtb+renesas at gmail.com>
>> > ---
>> > v3: same (only patch 0003 changed)
>> >
>> >  drivers/clocksource/sh_cmt.c |  109 +++++++++++++++++++++++++++++++++++++-----
>>
>>
>> This change appears to break booting of kzm9g-reference
>> with MMC enabled. I assume because it somehow causes CMT to
>> (once again) be initialised after SDHI and/or MMC.
>>
>> Tested using next with the defconfig + CONFIG_MACH_KZM9G_REFERENCE=y +
>> initrd root fs.
>

Thanks for finding this flaw. I've got it on my agenda.

Bastian

>> >  1 file changed, 96 insertions(+), 13 deletions(-)
>> >
>> > diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c
>> > index 08d0c41..79bc526 100644
>> > --- a/drivers/clocksource/sh_cmt.c
>> > +++ b/drivers/clocksource/sh_cmt.c
>> > @@ -34,10 +34,13 @@
>> >  #include <linux/module.h>
>> >  #include <linux/pm_domain.h>
>> >  #include <linux/pm_runtime.h>
>> > +#include <linux/of.h>
>> >
>> >  struct sh_cmt_priv {
>> >     void __iomem *mapbase;
>> >     struct clk *clk;
>> > +   long channel_offset;
>> > +   int timer_bit;
>> >     unsigned long width; /* 16 or 32 bit version of hardware block */
>> >     unsigned long overflow_bit;
>> >     unsigned long clear_bits;
>> > @@ -109,9 +112,7 @@ static void sh_cmt_write32(void __iomem *base, unsigned long offs,
>> >
>> >  static inline unsigned long sh_cmt_read_cmstr(struct sh_cmt_priv *p)
>> >  {
>> > -   struct sh_timer_config *cfg = p->pdev->dev.platform_data;
>> > -
>> > -   return p->read_control(p->mapbase - cfg->channel_offset, 0);
>> > +   return p->read_control(p->mapbase - p->channel_offset, 0);
>> >  }
>> >
>> >  static inline unsigned long sh_cmt_read_cmcsr(struct sh_cmt_priv *p)
>> > @@ -127,9 +128,7 @@ static inline unsigned long sh_cmt_read_cmcnt(struct sh_cmt_priv *p)
>> >  static inline void sh_cmt_write_cmstr(struct sh_cmt_priv *p,
>> >                                   unsigned long value)
>> >  {
>> > -   struct sh_timer_config *cfg = p->pdev->dev.platform_data;
>> > -
>> > -   p->write_control(p->mapbase - cfg->channel_offset, 0, value);
>> > +   p->write_control(p->mapbase - p->channel_offset, 0, value);
>> >  }
>> >
>> >  static inline void sh_cmt_write_cmcsr(struct sh_cmt_priv *p,
>> > @@ -176,7 +175,6 @@ static DEFINE_RAW_SPINLOCK(sh_cmt_lock);
>> >
>> >  static void sh_cmt_start_stop_ch(struct sh_cmt_priv *p, int start)
>> >  {
>> > -   struct sh_timer_config *cfg = p->pdev->dev.platform_data;
>> >     unsigned long flags, value;
>> >
>> >     /* start stop register shared by multiple timer channels */
>> > @@ -184,9 +182,9 @@ static void sh_cmt_start_stop_ch(struct sh_cmt_priv *p, int start)
>> >     value = sh_cmt_read_cmstr(p);
>> >
>> >     if (start)
>> > -           value |= 1 << cfg->timer_bit;
>> > +           value |= 1 << p->timer_bit;
>> >     else
>> > -           value &= ~(1 << cfg->timer_bit);
>> > +           value &= ~(1 << p->timer_bit);
>> >
>> >     sh_cmt_write_cmstr(p, value);
>> >     raw_spin_unlock_irqrestore(&sh_cmt_lock, flags);
>> > @@ -673,9 +671,85 @@ static int sh_cmt_register(struct sh_cmt_priv *p, char *name,
>> >     return 0;
>> >  }
>> >
>> > -static int sh_cmt_setup(struct sh_cmt_priv *p, struct platform_device *pdev)
>> > +static const struct of_device_id of_sh_cmt_match[] = {
>> > +   { .compatible = "renesas,cmt-timer" },
>> > +   {},
>> > +};
>> > +MODULE_DEVICE_TABLE(of, of_sh_cmt_match);
>> > +
>> > +static const int sh_cmt_offset_multiplier[] = { 0x60, 0x10, 0x40, 0x40, 0x40 };
>> > +#define CMT_MAX_CHANNELS   6
>> > +
>> > +static struct sh_timer_config *sh_cmt_parse_dt(struct device *dev)
>> > +{
>> > +   struct sh_timer_config *cfg;
>> > +   struct device_node *np = dev->of_node;
>> > +   u32 timer_id, channel_id, rating;
>> > +
>> > +   if (!IS_ENABLED(CONFIG_OF) || !np)
>> > +           return NULL;
>> > +
>> > +   cfg = devm_kzalloc(dev, sizeof(struct sh_timer_config), GFP_KERNEL);
>> > +   if (!cfg) {
>> > +           dev_err(dev, "failed to allocate DT config data\n");
>> > +           return NULL;
>> > +   }
>> > +
>> > +   if (of_property_read_u32(np, "renesas,device-id", &timer_id)) {
>> > +           dev_err(dev, "device id missing\n");
>> > +           return NULL;
>> > +   }
>> > +   if (timer_id >= ARRAY_SIZE(sh_cmt_offset_multiplier)) {
>> > +           dev_err(dev, "invalid device id\n");
>> > +           return NULL;
>> > +   }
>> > +
>> > +   if (of_property_read_u32(np, "renesas,channel-id", &channel_id)) {
>> > +           dev_err(dev, "channel id missing\n");
>> > +           return NULL;
>> > +   }
>> > +   if (channel_id >= CMT_MAX_CHANNELS) {
>> > +           dev_err(dev, "invalid channel id\n");
>> > +           return NULL;
>> > +   }
>> > +
>> > +   cfg->channel_offset = sh_cmt_offset_multiplier[timer_id] *
>> > +                                                   (channel_id + 1);
>> > +   cfg->timer_bit = channel_id;
>> > +
>> > +   /*
>> > +    * We convert the {source,event}-quality DT properties to linux specific
>> > +    * clock{source,event}_ratings.
>> > +    */
>> > +   if (!of_property_read_u32(np, "renesas,source-quality", &rating)) {
>> > +           if (rating > 10) {
>> > +                   dev_err(dev, "invalid source-quality\n");
>> > +                   return NULL;
>> > +           }
>> > +           if (rating)
>> > +                   cfg->clocksource_rating = rating * 50 - 1;
>> > +   }
>> > +
>> > +   if (!of_property_read_u32(np, "renesas,event-quality", &rating)) {
>> > +           if (rating > 10) {
>> > +                   dev_err(dev, "invalid event-quality\n");
>> > +                   return NULL;
>> > +           }
>> > +           if (rating)
>> > +                   cfg->clockevent_rating = rating * 50 - 1;
>> > +   }
>> > +
>> > +   if (!cfg->clocksource_rating && !cfg->clockevent_rating) {
>> > +           dev_err(dev, "source- and event-quality 0, timer is unused\n");
>> > +           return NULL;
>> > +   }
>> > +
>> > +   return cfg;
>> > +}
>> > +
>> > +static int sh_cmt_setup(struct sh_cmt_priv *p, struct platform_device *pdev,
>> > +                                           struct sh_timer_config *cfg)
>> >  {
>> > -   struct sh_timer_config *cfg = pdev->dev.platform_data;
>> >     struct resource *res;
>> >     int irq, ret;
>> >     ret = -ENXIO;
>> > @@ -762,6 +836,9 @@ static int sh_cmt_setup(struct sh_cmt_priv *p, struct platform_device *pdev)
>> >             goto err2;
>> >     }
>> >
>> > +   p->channel_offset = cfg->channel_offset;
>> > +   p->timer_bit = cfg->timer_bit;
>> > +
>> >     platform_set_drvdata(pdev, p);
>> >
>> >     return 0;
>> > @@ -777,7 +854,7 @@ err0:
>> >  static int sh_cmt_probe(struct platform_device *pdev)
>> >  {
>> >     struct sh_cmt_priv *p = platform_get_drvdata(pdev);
>> > -   struct sh_timer_config *cfg = pdev->dev.platform_data;
>> > +   struct sh_timer_config *cfg;
>> >     int ret;
>> >
>> >     if (!is_early_platform_device(pdev)) {
>> > @@ -785,6 +862,11 @@ static int sh_cmt_probe(struct platform_device *pdev)
>> >             pm_runtime_enable(&pdev->dev);
>> >     }
>> >
>> > +   if (pdev->dev.of_node)
>> > +           cfg = sh_cmt_parse_dt(&pdev->dev);
>> > +   else
>> > +           cfg = pdev->dev.platform_data;
>> > +
>> >     if (p) {
>> >             dev_info(&pdev->dev, "kept as earlytimer\n");
>> >             goto out;
>> > @@ -796,7 +878,7 @@ static int sh_cmt_probe(struct platform_device *pdev)
>> >             return -ENOMEM;
>> >     }
>> >
>> > -   ret = sh_cmt_setup(p, pdev);
>> > +   ret = sh_cmt_setup(p, pdev, cfg);
>> >     if (ret) {
>> >             kfree(p);
>> >             pm_runtime_idle(&pdev->dev);
>> > @@ -824,6 +906,7 @@ static struct platform_driver sh_cmt_device_driver = {
>> >     .remove         = sh_cmt_remove,
>> >     .driver         = {
>> >             .name   = "sh_cmt",
>> > +           .of_match_table = of_match_ptr(of_sh_cmt_match),
>> >     }
>> >  };
>> >
>> > --
>> > 1.7.9.5
>> >
>> > --
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